The Review of Laser Engineering
Online ISSN : 1349-6603
Print ISSN : 0387-0200
ISSN-L : 0387-0200
Search
Advanced search
OR
Browse
Search
Volume 28, Issue 1
Displaying 1-14 of 14 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • [title in Japanese]
    Takashi KUSHIDA
    2000 Volume 28 Issue 1 Pages 1
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.1
    JOURNAL FREE ACCESS
    Download PDF (188K)
  • Recent Laser Technology and Its Applications to Material Processing
    Haruhiko NAGAI
    2000 Volume 28 Issue 1 Pages 2
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.2
    JOURNAL FREE ACCESS
    Download PDF (187K)
  • Micro-Processing by Diode-Laser Pumped Solid-State Lasers
    Keiichi KUBOTA
    2000 Volume 28 Issue 1 Pages 3-8
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.3
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Micro-processing application by Diode laser-pumped solid-state lasers is reviewed. Diode-laser pumped solid-state lasers are very suitable for micro-processing because of high peak power, short pulse width, wavelength, small size, little power consumption and maintenance free characteristics. In the electrical industries laser micro-processing machines have been installed for trimming, marking, repairing, micro-via drilling and 3D forming. Higher power and lower cost of diode-laser pumped solid-state lasers will be achieved in near future and their application will be extended into lithography fields and welding application.
    View full abstract
    Download PDF (1577K)
  • Processing Performances of High Power Zigzag-Slab Type Nd: YAG Lasers
    Nobuaki IEHISA, Hiroyuki YOSHIDA, Yoshitake FURUYA, Hitoshi ENOKIZONO, ...
    2000 Volume 28 Issue 1 Pages 9-12
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.9
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    The optical distortions such as thermal focusing effect and birefringence in the crystal of high power Nd: YAG lasers have been dramatically reduced by employing both zigzag-slab type crystal and 2-pass resonator. The beam quality of the zigzag-slab type Nd: YAG laser oscillator with an average power of 500W is better than 15mm-mrad in the width direction and 5mm-mrad in the thickness direction. The processing performances of developed high power Nd: YAG laser oscillators with high beam quality are introduced here.
    View full abstract
    Download PDF (802K)
  • High Power YAG Laser Application for Heavy Component Welding and Cutting
    Takashi ISHIDE, Shuho TSUBOTA, Michisuke NAYAMA, Yoshiaki SHIMOKUSU, T ...
    2000 Volume 28 Issue 1 Pages 13-18
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.13
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    We initially applied the 6kW to 10kW YAG lasers in order to weld and cut heavy components. We used optical fiber beam guide systems whose core diameters are 0.6mm to 0.8mm in length and having a standard length of 200m. Using the above systems we can realize a penetration depth of 15mm to 20mm per pass. Multi-pass welding is utilized for thicker plates. Data is also given for nuclear power plant dismantling in which 100mm thick plates are cut. These systems were used in conjunction with CCD camera image processing which monitored the systems in process. Monitoring fibers were placed co-axial to the YAG optical lens system during the in-process monitoring by means of a monitoring fiber. Light intensity emanating from the cutting or welding area was measured during the monitoring. Furthermore, we have developed a new hybrid welding system using TIG electrode located in the center of the lens. This ensures that high power can be maintained. This hybrid welding system (TIG-YAG) aims to decrease welding groove allowances and improve the quality of welding. It also enables arc and laser welding to be carried out simultaneouslyby positioning the TIG electrode in the center of the YAG optical lens. Through these techniques we have applied a 7kW class YAG laser to weld nuclear power plant components.
    View full abstract
    Download PDF (1922K)
  • [title in Japanese]
    2000 Volume 28 Issue 1 Pages 18-18,23
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.18
    JOURNAL FREE ACCESS
    Download PDF (631K)
  • Micro-Drilling of Advanced Electric Boards with a High-Peak Power CO2 laser
    Yukio SATO, Juniti NISHIMAE, Akihiko IWATA, Shouzui TAKENO, Tsukasa FU ...
    2000 Volume 28 Issue 1 Pages 19-23
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.19
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Micro-hole drilling of advanced printed boards with a CO2 laser is revealed. The applied high-peak power CO2 laser has a pulse duration shorter than 100 μs and a peak power level in the kW-range. Thedesign of the laser system and its implementation into a processing system lead to an industrial laser drilling system which is able to process minimum hole diameters of 50 μm. Some examples of micro-drilling results are described.
    View full abstract
    Download PDF (1132K)
  • Poly-Silicon TFT Annealing with XeCl Excimer Laser
    Junichi SHIDA, Naoyuki KOBAYASHI, Hideaki KUSAMA
    2000 Volume 28 Issue 1 Pages 24-28
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.24
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Liquid-crystal displays (LCDs) with thin film transistors (TFTs) are common in digital and video cameras. An Excimer-Laser Annealing (ELA) method is now commonly integrated into a low-temperature poly-silicon (p-Si) TFT process. Since the ELA process can be performed below 400°C, it is possible to use a low-cost standard glass instead of a quartz glass as a TFT substrate. Our ELA system with a XeCl excimer laser has a line beam optic system, handling the beam length of up to 275mm. The line beam scans an amorphous-silicon (a-Si) thin film on the substrate. As a result, the a-Si film changes into the p-Si film immediately. We demonstrated crystallization of a-Si thin films on different annealing conditions such as various laser energy levels and various substrate temperatures. It was found that the crystal-grain size of the p-Si film strongly depends on both the energy density and the substrate temperature.
    View full abstract
    Download PDF (1020K)
  • UV Laser Ablative Figuring of Optical Elements
    Takahisa JITSUNO, Keiu TOKUMURA, Hisashi TAMAMURA
    2000 Volume 28 Issue 1 Pages 29-33
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.29
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    A new method has been developed for producing precise optical elements using ArF excimer laserablation of plastic materials together with the wavefront measurement instruments. The ablative figuring of optical plastic coated on the glass substrate is made very successfully for obtaining a desired phase profile.The wavefront distortion of 3 λ, is improved to 0.2 λ by 3 times iterations on the plate of 50mm in diameter. The phase error compensation of micro-lens for high power laser diode has been tried for direct application ofLD for industrial use. The ablative figuring of glass and quartz materials have been also examined, and the absorption process of ArF and F
    2 laser was studied by time resolved transmittance measurement.
    View full abstract
    Download PDF (1082K)
  • Materials Processing by High Power and High Power Density Diode Laser
    Nobuyuki ABE
    2000 Volume 28 Issue 1 Pages 34-39
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.34
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Recently, high power and high power density diode lasers have been developed for their superiority of conversion efficiency as compared to conventional CO2 or Nd: YAG lasers. Materials processing using these lasers are reviewed and the 2kW class high power density diode laser is introduced in relation to its materials processing characteristics.
    View full abstract
    Download PDF (2027K)
  • Inner Glass Marking by Controlled Optical Damage Formation
    Kenichi HAYASHI
    2000 Volume 28 Issue 1 Pages 40-44
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.40
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Inner marking was performed using harmonics of a solid-state laser. A Gaussian-like profile LD-pumped Nd: YLF laser was employed to generate the second harmonic (523nm) pulses. When the laser beam was sharply focused inside the transparent material, the phenomena of optical damage or optical breakdown occurred inside the material. Highly controlled optical damage formation made it possible to produce machinereadable marking inside the thin glass substrate without any surface damage. The mechanism of inner marking is discussed. Inner glass marking is suitable for clean industrial marking processes.
    View full abstract
    Download PDF (2489K)
  • Keyhole Behavior during High Power YAG Laser Welding
    Shigeki FUJINAGA, Hiroo TAKENAKA, Toru NARIKIYO, Seiji KATAYAMA, Akira ...
    2000 Volume 28 Issue 1 Pages 45-49
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.45
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    In laser welding, power density is very high at the processing points and a cavity called a keyhole is generated by the recoil pressure of evaporation. The authors examined keyhole and plasma/plume behavior using a microfocused X-ray transmission in-situ imaging system and a high speed video camera during spot welding and bead-on-plate welding of SUS304 stainless steel. The following results were observed. The keyhole was generated to a small degree by the first shot of a 26 J pulsed beam and became gradually deeper by increasing the number of shots in spot welding. When a pulsed laser beam of 1.1 ms in rise time and 7.6kW in peak power was used in bead-on-plate welding, the plasma/plume began to be generated in about 0.22ms after the initiation of laser beam irradiation, the keyhole began to form after about 0.6 or 0.7ms, became its deepest after about 1.5ms from the start of laser irradiation, and disappeared after about 1.3ms following the laser termination. The keyhole formation time was 0.6ms in rise time and the average velocity of keyhole growth was about 6m/s at this time.
    View full abstract
    Download PDF (843K)
  • Flashlamp Simmer Circuit Using a Cockcroft Circuit
    Akihiro YAMAMURA, Tetsuo KANO, Haruo UCHIYAMA, Masanori JYUMONJI
    2000 Volume 28 Issue 1 Pages 50-53
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.50
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Pre-discharge of the excitation flashlamp has been effectively applied to solid state and dyelasers in order to stabilize and increase their laser output. This technique is known as a simmer discharge or simmer mode. Because the starting voltage in glow discharge greatly exceeds the voltage required for steady state glow discharge, a very high voltage power supply is required. Alternatively, a high voltage trigger circuit can be used in conjunction with the standard high voltage power supply. In this paper, we propose a new simmer discharge circuit using a Cockcroft circuit which has relatively low voltage regulation, and discuss its performance.
    View full abstract
    Download PDF (589K)
  • Fundamentals of Laser Spectroscopy II
    Luminescence Spectroscopy
    Tadashi ITOH
    2000 Volume 28 Issue 1 Pages 54-59
    Published: January 15, 2000
    Released on J-STAGE: March 17, 2010
    DOIhttps://doi.org/10.2184/lsj.28.54
    JOURNAL FREE ACCESS
    Download PDF (1052K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top